LET US START WITH A DEMONSTRATION, (AFTER A STUDY BY LEE BROOKS-OF McMASTER UNIVERSITY)...SEE P. 101

-WHY IS IT THAT WE FIND IT DIFFICULT TO PERFORM SOME TASKS SIMULTANOUSLY... KEEPING A MENTAL IMAGE IN OUR MIND WHILE DOING A SPATIAL TASK (POINTING) BUT NOT WHILE DOING A VERBAL TASK

AND: KEEPING A SENTENCE IN MIND WHILE DOING A VERBAL TASK (BUT NOT THE SPATIAL POINTING TASK)

AN EXAMPLE OF CHANNEL SEGREGATION; DUE TO THE FACT THAT IMAGERY AND SPATIAL ACTIVITIES ARE DIFFICULT TO DISCRIMINATE FROM ONE ANOTHER BECAUSE THEY USE OR SHARE COMMON PROCESSES (AND ANALOGOUSLY THAT TALKING AND THINKING ABOUT SENTENCES SHARE COMMON PROCESSES)

SUGGESTS THAT OUR VISUAL IMAGE AND OUR LANGUAGE FUNCTIONS ARE FUNCTIONALLY INDEPENDENT

ARGUES FOR TWO DISTINCT FORMS OF REPRESENTATION: ONE TIED TO SENSORY EXPERIENCE (IMAGERY SYSTEM)

THAT IS, THE FORMAT FOR VISUAL KNOWLEDGE IS DEPICTIVE: THE MENTAL IMAGE IS TIED TO PERCEPTUAL EXPERIENCE AND IS REPRESENTED IN A WAY THAT MAINTAINS PICTURE-LIKE
CHARACTERISTICS

BUT HE ARGUES THAT WE ACQUIRE SOME KNOWLEDGE IN A WAY THAT IS LESS TIED TO SENSORY INPUT, VIA LANGUAGE (ORAL) OR VIA READING... THUS OUR KNOWLEDGE THAT THE CHEMICAL COMPOSITION OF TABLE SALT IS NaCl IS NOT DIRECTLY RELATED TO SENSORY EXPERIENCE.
THIS KNOWLEDGE HE AVERS IS REPRESENTED IN A VERBAL SYSTEM (WHICH HAS CHARACTERISTICS QUITE DIFFERENT FROM THAT OF THE IMAGERY SYSTEM. .e.g., THE VERBAL SYSTEM IS AMODAL, DOESN'T MAINTAIN A SPATIAL FORMAT)

1. IF IMAGES ARE DEPICTIVE, THEY SHOULD BE ANALOGUES OF THE REAL WORLD.

DO IMAGES "POSSESS" SPATIAL EXTENT

e.g., SCANNING STUDIES (P.399)

DOES THE MANIPULATION OF AN IMAGE TAKE "REAL TIME"

e.g., MENTAL ROTATION STUDIES (P.404)

2. IF IMAGES ARE DERIVED FROM SENSORY INPUT, THEN DO IMAGES AND PERCEPTION SHARE COMMON FEATURES, AND PROCESSING MODULES?

E.g., INTERFERENCE OF PERCEPTS AND IMAGES... THE PERKY EFFECT

E.g., PARALLEL FINDINGS WHEN ONE PERFORMS A PERCEPTUAL TASK (STIMULUS PRESENT) AND THE SAME TASK PERFORMED FROM ON THE MENTAL IMAGE

E.g., CORRELATING BRAIN ACTIVITY WITH TASK DONE IMAGINALLY AND PERCEPTUALLY

• f MRI
• BRAIN DAMAGE AND "VISUAL NEGLECT"

• THE CASE OF AMBIGUOUS FIGURES
• CAN WE CHANGE THE INTERPRETATION OF THE IMAGE IN THE SAME WAY THAT WE CAN FOR THE PERCEPTUAL COUNTERPART